Splenda Reduces Gut Bacteria in Rats

This 2008 study done at Duke University found that small amounts of Splenda — similar to what a person might consume — reduced “beneficial bacteria” in the guts of rats. The effect was very large (reduction by about 50% in 12 weeks) and occurred even at the lowest dose, which was lower than what the FDA allows. Most ominous of all, the effect had not levelled off after 12 weeks. The number of bacteria was still going down.

Within a day two different people told me (in the comments to this blog) about this study, which was published a year ago. A press release about the study. The research was funded by the Sugar Association. Someone recently told me that the only way doctors learn about bad side effects of this or that drug is when drug reps selling competing drugs tell them. While reading about this I came across this chilling comment:

Excitotoxins are implicated in Parkinson’s as well… makes you wonder about Michael J. Fox – his time as Diet Pepsi’s spokesperson and his admitted addiction to the stuff for decades. I remember seeing an interview with him. His head was shaking from the Parkinson’s and his Diet Pepsi was right next to him.

One of the authors of the Duke study is a professor of psychiatry, Susan Schiffman. An earlier study of hers had pro-Splenda results.

More The makers of Splenda issued a press release that could not be less convincing. The study, it says, has “major deficiencies” that include “a lack of appropriate control groups necessary for understanding results.” No statement of what those control groups are. The press release also claims that because the investigators did not measure food and water intake, the results are meaningless! The idiotic press release is made even more curious by the statement quoted in the comments below, that “Drs. Abou-Donia and Schiffman admitted that some of the results recorded in their report submitted to the court were not actually observed or were based on experiments that had not been conducted.” But these, too, are not described. Which means to me that the details are not on Splenda’s side, or they would have been presented. It sounds like really bad news for Splenda.

17 Responses to “Splenda Reduces Gut Bacteria in Rats”

  1. Nathan Henderson Says:

    From a press release from McNeil Nutritionals, creators of Splenda:

    “Drs. Mohamed Abou-Donia and Susan Schiffman are the principal authors of the study dismissed by the judge. During depositions in ongoing litigation between the Sugar Association and McNeil Nutritionals, LLC, Drs. Abou-Donia and Schiffman admitted that some of the results recorded in their report submitted to the court were not actually observed or were based on experiments that had not been conducted.”

    Fabricated results? That doesn’t exactly instill confidence.

  2. seth Says:

    Thanks for uncovering this Nathan. I will try to find out what they are talking about.

  3. Mike Kenny Says:

    I use a lot of Splenda in my coffee. Is there anything one might notice if one’s stomach’s good bacteria were diminished 50%?

  4. Nathan Myers Says:

    Bad news for people suckered into eating Splenda. For Splenda itself, what it is is old news; they knew about this at least a year ago.

  5. JLD Says:

    Why not trying Stevia if you are hooked on sweet tastes?

  6. Darrin Thompson Says:

    The anti-splenda press release is from “national consumer education group Citizens for Health” which doesn’t exactly inspire confidence either. I mean, come on, Citizens for Health? Could you make the name sound any more like a PR shell?

    Anyone able to see the actual study?

  7. Sheila Says:

    Benefits of Stevia:
    * Sugarless with no calories
    * Will not effect blood sugar levels like sugar does.
    * 100% Natural
    * 250 to 300 times sweeter than sugar
    * Heat stable to 200 degrees Celsius (392 degrees Fahrenheit)
    * Non-fermentable
    * Flavor enhancer
    * Plaque retardant Anti-caries (prevents cavities)
    * Recommended for diabetics
    * Non-toxic Extensively tested in animals and Extensively used by humans with no adverse effects.

    Stevia has been used in Japan since 1970 and there have been no reports of toxicity or other side effects. The Japanese Food and Drug Safety Center has found stevia not to be mutagenic. Only one study has shown stevia to be potentially a mutagenic and this study has been criticized for errors in procedure. Scientist in Great Britain said that according to the study’s formula, distilled water is mutagenic. Two studies showed stevia to have a contraceptive effect. The first study was done in Uruguay over 30 years ago and since then no one has been able to reproduce the results. The second study was done by a graduate student in Rio de Janeiro and the results and methods have been questionable. Multiple other studies have shown that stevia has no contraceptive effect.
    * Is Stevia Safe? Absolutely. Stevia has been used around the world with NO reports of stevia overdose or toxicity to humans in the past forty years.

    What are the benefits of Using Stevia? Studies have shown the following benefits from using Stevia in one’s diet. These benefits have not been approved or confirmed by the FDA.

    Splenda on the other hand is made from binding chlorine with sugar….to me, the choice is obvious.

  8. Keane Says:

    I think diet Pepsi would have been using a different sweetener than Splenda,
    maybe aspartame. Certainly a diffent chemical, from Splenda.

    Are all man made sweeteners harmful? Does natural source necessarily
    mean more beneficial?

  9. seth Says:

    “Are all man-made sweeteners harmful?” It is beginning to look that way. One reason there are so many is that problems keep being identified long after FDA approval. Certainly they are more dangerous than we are led to believe.

    Yes, Diet Pepsi is sweetened with aspartame (Nutrasweet), not Splenda (sucralose).

  10. Study: Splenda kills beneficial bacteria in GI tract | Les Jones Says:

    [...] Seth Roberts – Splenda Reduces Gut Bacteria in Rats: This 2008 study done at Duke University found that small amounts of Splenda — similar to what a person might consume — reduced “beneficial bacteria” in the guts of rats. The effect was very large (reduction by about 50% in 12 weeks) and occurred even at the lowest dose, which was lower than what the FDA allows. Most ominous of all, the effect had not levelled off after 12 weeks. The number of bacteria was still going down. [...]

  11. smeach Says:

    I have a copy of the article. Unfortunately, copywright law prohibits me from sharing my personal copy.

    However, if you type “Abou-Donia and splenda,” on Google Scholar, you may find a link to the article.

  12. Ted Says:

    Since aspartme is actually used as an ingredient in ‘lite’ yogurts, is it safe to assume that aspartme is unlikely to chase off gut bacteria in the same way?

  13. John H Says:

    To me, Stevia tastes more bitter than sweet. So until this controversy about Splenda is cleared up, I think I may have to go back to aspartame (Equal). Better to run a small increased risk of brain cancer (if even that–see Seth’s previous posts on aspartame and readers’ comments) than this?

  14. KS Says:

    I retrieved the paper using Google Scholar, and discovered this acknowledgment: “This research was supported in part by a grant from the Sugar Association,
    Inc., Washington, DC”

    In other words, the study cannot be assumed to be entirely unbiased.
    This is not to say that the findings are not valid — they might be.
    (I hope not, since I’ve been using Splenda, having switched from aspartame due to concerns about its safety.) But when a competing interest is funding a study, the results need to be viewed with some skepticism.

  15. Alexandra Carmichael Says:

    Hi Seth,

    This is fascinating. What about xylitol? Due to its antibacterial/cavity-preventing properties, we are considering giving it to our daughter who is prone to cavities. Any idea if it would affect the bacteria in her gut?

    Thanks for your thoughts, and for always posting such thought-provoking pieces.
    Alex :)

  16. seth Says:

    Thanks, Alex. I don’t know about xylitol, sorry. In Nutrition and Physical Degeneration (available online), Weston Price has a lot to say, based on data, about what foods do and don’t cause cavities. I don’t know if his ideas will be helpful, because they sort of boil down to modern food is bad, but you might learn something useful from it.

  17. Joseph Says:

    For the past six to nine months, after using Splenda for a year or more in my coffee at WORK, I’ve been having horrible acid mouth, throat, heartburn, even my eyes burning.

    Nothing my doctor tried worked. Lots of probiotics and enzymes helped somewhat.

    It always seems to be less on the weekends (I use mostly Palm Sugar on the weekends)–I just found out about this study a few days ago. I stopped using Splenda right away. Things seemed improved a little. I guess time will tell.

    Thanks for posting this.